AROMATIC POLY(ETHER IMIDE)S BEARING ISOPROPYLIDENE OR HEXAFLUOROISOPROPYLIDENE LINKS IN THE MAIN-CHAIN

Two bis(ether anhydride) monomers, 2,2-bis[4-(3,4-dicarboxyphenoxy)phe nyl]propane dianhydride (4) and s[4-(3,4-dicarboxyphenoxy)phenyl]hexaf luoropropane dianhydride (4-F), were synthesized from readily availabl e compounds in three steps in high yields. Two series of poly(ether im ide)s 7(a-g) and 7(a-g)-F based on dianhydrides 4 and 4-F, respectivel y, were synthesized by a conventional two-step procedure that included a ring-opening polyaddition to give polyamic acid)s, followed by cycl odehydration to polyimides. The intermediate poly(ether amic acid)s an d the poly(ether imide)s had inherent viscosities in the range of 0.29 -1.09 dL g(-1) and 0.21-0.98 dL g(-1), respectively. Except for the po ly(ether imide)s derived from benzidine, the others afforded flexible and tough films. Most of the obtained poly(ether imide)s are organic-s oluble. The glass transition temperatures (T-g) of these polymers rang ed from 204 to 259 degrees C. Degradation temperatures for 10% weight loss all occurred above 505 degrees C in nitrogen and above 501 degree s C in air. Fluorine-containing polyether imide)s showed higher solubi lity, T(g)s and degradation temperatures in nitrogen, as compared to t heir respective nonfluorine-containing counterparts.